Aqueous bleaching formulations

ABSTRACT

The invention relates to new aqueous bleaching formulations containing 
     1 to 10% by weight of peroxide compounds, 
     1 to 2.5% by weight of fatty alcohol ether sulfates 
     0.4 to 1.0% by weight of narrow-range fatty alcohol polyglycol ethers and 
     1 to 2.5% by weight of electrolytes. 
     The formulations are distinguished by advantageous viscosity, a cloud point of at least 20° C. and high stability in storage.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to aqueous bleaching formulations containingperoxide compounds, fatty alcohol ether sulfates, narrow-range fattyalcohol polyglycol ethers and electrolytes.

2. Discussion of Related Art

In the past, bleaching formulations based on hydrogen peroxide whichshow remarkable viscosity and, accordingly, are suitable both fortreating horizontal surfaces and for treating sloping and, above all,vertical surfaces have been successfully used in the fields of hygieneand disinfection. The effect of the viscosity of these bleachingformulations is that the contact time between the bleaching formulationand the surface to be treated is considerably longer than in the case ofcommercial liquid products which quickly flow off from the surface.

Accordingly, there has been no shortage of attempts to provide viscousbleaching formulations of the type in question. Spanish patentapplication ES 88/1389 (Henkel Iberica), for example, proposes aqueousbleaching and disinfecting formulations based on alkali metalhypochlorites which are thickened by addition of fatty alcohol ethersulfates. However, ether sulfates are unsuitable on their own foradjusting the viscosity of bleaching formulations containing hydrogenperoxide. They give products of very low viscosity which turn cloudy atlow temperatures and are not sufficiently stable in storage.

Accordingly, the problem addressed by the present invention was toprovide new bleaching formulations containing peroxide compounds whichwould have an advantageous viscosity of at least 100 mPa.s, a cloudpoint of at least 20° C. and high stability in storage.

DESCRIPTION OF THE INVENTION

The present invention relates to aqueous bleaching formulationscontaining

1 to 10% by weight of peroxide compounds,

1 to 2.5% by weight of fatty alcohol ether sulfates

0.4 to 1.0% by weight of narrow-range fatty alcohol polyglycol ethersand

1 to 2.5% by weight of electrolytes.

It has surprisingly been found that the addition of fatty alcohol ethersulfates, fatty alcohol polyglycol ethers and electrolyte salts inselected quantity ratios leads to excellent thickening of aqueoushydrogen peroxide solutions. The products obtained are extremely stablein storage both in regard to their viscosity and in regard to theirperoxide content and have a cloud point of at least 20° C.

Peroxide Compounds

Peroxide compounds in the context of the present invention areunderstood to be substances containing an O--O group. Typical examplesare perborates, percarbonates, percarboxylic acids and, in particular,hydrogen peroxide. In a preferred embodiment, the aqueous bleachingformulations according to the invention contain hydrogen peroxide inquantities of 1 to 10% by weight, preferably 5 to 8% by weight and morepreferably 6 to 7% by weight, based on 100% of active substance. Theperoxide compounds are used, for example, in the form of a 35% by weightaqueous solution.

Fatty Alcohol Ether Sulfates

Fatty alcohol ether sulfates ("ether sulfates") are known anionicsurfactants which are industrially produced by the sulfation of fattyalcohol polyglycol ethers with SO₃ or CSA and subsequent neutralization.

According to the invention, suitable ether sulfates correspond toformula (I):

    R.sup.1 O--(CH.sub.2 CH.sub.2 O).sub.m SO.sub.3 X          (I)

in which R¹ is a linear or branched alkyl and/or alkenyl radicalcontaining 6 to 22 carbon atoms, m is a number of 1 to 10 and X is analkali metal and/or alkaline earth metal, ammonium, alkylammonium,alkanolammonium or glucammonium.

Typical examples are the sulfates of adducts of on average 1 to 10 and,more particularly, 2 to 5 moles of ethylene oxide with caproic alcohol,caprylic alcohol, 2-ethylhexyl alcohol, capric alcohol, lauryl alcohol,isotridecyl alcohol, myristyl alcohol, cetyl alcohol, palmitoleylalcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidylalcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol,behenyl alcohol and erucyl alcohol and technical mixtures thereof in theform of their sodium and/or magnesium salts. The ether sulfates may haveboth a conventional homolog distribution and a narrow homologdistribution.

It is particularly preferred to use ether sulfates based on adducts of,on average, 2 to 3 moles of ethylene oxide with technical C_(12/14) orC_(12/18) cocofatty alcohol fractions in the form of their sodium and/ormagnesium salts.

NRE Fatty Alcohol Polyglycol Ethers

Fatty alcohol polyglycol ethers with a narrow homolog distribution,which are also known as narrow-range ethoxylates (NRE), are knownnonionic surfactants which are industrially produced, for example, byaddition of ethylene oxide onto fatty alcohols in the presence ofsuitable catalysts (layer compounds which have been calcined orhydrophobicized with fatty acids). Reviews on this subject arepresented, for example, by M. Cox in J. Am. Oil. Chem. Soc. 67, 599(1990) and by H. Hensen et al. in Seifen-Ole-Fette-Wachse, 117, 592(1991).

According to the invention, suitable ethers correspond to formula (II):

    R.sup.2 O--(CH.sub.2 CH.sub.2 O).sub.m H                   (II)

in which R² is a linear or branched alkyl and/or alkenyl radicalcontaining 6 to 22 carbon atoms, m is a number of 1 to 10.

Typical examples are narrow-range adducts of on average 1 to 10 and,more particularly, 2 to 5 moles of ethylene oxide with caproic alcohol,caprylic alcohol, 2-ethylhexyl alcohol, capric alcohol, lauryl alcohol,isotridecyl alcohol, myristyl alcohol, cetyl alcohol, palmitoleylalcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidylalcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol,behenyl alcohol and erucyl alcohol and the technical mixtures thereofobtained, for example, in the high-pressure hydrogenation of technicalmethyl esters based on fats and oils or aldehydes from Roelen'soxosynthesis with a narrow homolog distribution.

Narrow-range adducts of, on average, 2 to 5 moles of ethylene oxide withtechnical C₁₂₋₁₈ fatty alcohols, such as for example coconut oil, palmoil, palm kernel oil or tallow fatty alcohol, are preferred. The use ofsuch substances as thickeners for cosmetic products, such as hairshampoos for example, is known from DE-A1 38 17 415 (Henkel). They arepreferably used in a concentration of 0.7 to 1.0% by weight.

Electrolytes

Suitable electrolyte salts are alkali metal or alkaline earth metalsalts of mineral acids and mixtures thereof which are known in principleas auxiliaries for adjusting the viscosity of aqueous surfactantsolutions. Typical examples are sodium chloride and/or magnesiumchloride.

Auxiliaries and Additives

Suitable auxiliaries and additives are, for example, otherperoxide-stable surfactants and hydrotropes such as, for example, alkylsulfates, alkyl sulfonates, alkyl benzene sulfonates, xylene sulfonates,sarcosinates, taurides, isethionates, sulfosuccinates, ether carboxylicacids, betaines, sugar esters, amine oxides and alkyl oligoglycosides.The sum total of these additional surfactants preferably makes up atmost 10% by weight of the total quantity of surfactants in theformulation.

In addition, the bleaching formulations may contain lower alcohols, suchas ethanol or isopropyl alcohol, peroxide-stable fragrances, opticalbrighteners, anti-oxidants, sequestrants, dyes and pigments in totalquantities of 0.01 to 0.5% by weight, based on the bleachingformulation. Known peroxide-stable fragrances include, for example,monocyclic and bicyclic monoterpene alcohols and esters thereof withacetic or propionic acid (for example isoborneol, dihydroterpenol,isobornyl acetate, dihydroterpenyl acetate). The optical brighteners maybe, for example, the potassium salt of4,4'-bis-(1,2,3-triazolyl)-(2-)-stilbene-2,2-sulfonic acid which ismarketed as Phorwite® BHC 766 and Tinopal CBS-X (Ciba). Examples ofsuitable antioxidants are ditert.butyl hydroxytoluene (BHT),ditert.butyl hydroxyanisole (BHA), tocopherol (vitamin E), ascorbic acidand ascorbic acid palmitate, optionally in combination with citric acid.Suitable sequestering agents are phosphonic acids or amine oxidephosphonic acids. Finally, suitable colored pigments are inter aliagreen chlorophthalocyanines (Pigmosol® Green, Hostaphine® Green), yellowSolar Yellow BG 300 (Sandoz) or red Rojo Basazol®.

The bleaching formulations according to the invention are produced bystirring. The product obtained may optionally be decanted or filtered toremove foreign particles and/or agglomerates.

Commercial Applications

The bleaching formulations according to the invention are clear atambient temperature, are sufficiently thick for application to verticalsurfaces and are stable in regard to their viscosity and peroxidecontent, even when stored for prolonged periods at elevated temperature.They are suitable, for example, for the cleaning and disinfection ofhard surfaces, for example in the sanitary field. In one particularembodiment of the invention, the paste-form bleaching formulations aredirectly applied to fibers for the pretreatment of soiled textiles.

A typical bleaching formulation according to the present invention hasthe following composition (water to 100% by weight):

7% by weight hydrogen peroxide

2% by weight C_(12/14) fatty alcohol 2EO sulfate sodium salt

0.7% by weight C_(12/14) fatty alcohol 2EO (NRE)

2% by weight sodium chloride

The following Examples are intended to illustrate the invention withoutlimiting it in any way.

EXAMPLES

I. Substances Used

A) Hydrogen peroxide in the form of a 21% by weight aqueous solution

B) C_(12/14) cocofatty alcohol 2EO ether sulfate sodium salt Texapon® N,Henkel KGaA, Dusseldorf/FRG

C) Narrow-range C_(12/14) cocofatty alcohol 2EO adduct Arlypon® F,Henkel KGaA, Dusseldorf/FRG

The composition of formulations F1 to F3 according to the invention andcomparison formulations F4 to F9 are set out in Table 1.

All the formulations contain 0.05% by weight of sequestering agent(Sequion®), 0.01% by weight of BHT, 0.1% by weight of isopropyl alcohol,0.2% by weight of perfume oil, 0.00035% by weight of dye and water to100% by weight.

                  TABLE 1                                                         ______________________________________                                        Formulations used                                                                  c(H.sub.2 O.sub.2)                                                                      c(FAES)     c(FAE)  c(NaCl)                                    F    % by weight                                                                             % by weight % by weight                                                                           % by weight                                ______________________________________                                        F1   7.5       2.00        0.700   2.00                                       F2   7.5       2.00        0.700   2.50                                       F3   7.5       2.00        0.810   2.00                                       F4   7.5       2.00        0.550   2.00                                       F5   7.5       2.50        0.550   2.00                                       F6   7.5       2.00        0.550   2.50                                       F7   7.5       2.50        0.550   2.50                                       F8   7.5       2.25        0.625   2.25                                       F9   7.5       2.00        0.550   2.88                                       ______________________________________                                         Legend:                                                                       c = Concentration                                                             FAES = Fatty alcohol ether sulfate                                            FAE = Fatty alcohol polyglycol ether                                     

II. Performance Tests

To evaluate performance, the Brookfield viscosity of the formulations(20° C., 20 r.p.m., spindle 1 to 2), their cloud point and the reductionin their peroxide content after storage for 4 weeks and 12 weeks (40°C.) were determined. The results are set out in Table 2.

                  TABLE 2                                                         ______________________________________                                        Viscosity, cloud point and stability                                                       Viscosity                                                                              Cloud point                                                                             K.sub.2 O.sub.2  % by weight!                 Ex. F        mpa · s                                                                       °C.                                                                              4 w   12 w                                    ______________________________________                                        1   F1       163      20        7.5   7.5                                     2   F2       105      20        7.5   7.5                                     3   F3       107      25        7.5   7.5                                     C1  F4        47      1         7.4   7.3                                     C2  F5        16      0         7.4   7.3                                     C3  F6       265      1         7.4   7.2                                     C4  F7        91      0         7.4   7.3                                     C5  F8       565      1         7.4   7.3                                     C6  F9        99      1         7.4   7.3                                     ______________________________________                                    

We claim:
 1. An aqueous bleaching composition having a viscosity of atleast 100 mPa.s at about 20° C. and a cloud point of at least 20° C.consisting essentially of1 to 10% by weight of a peroxide compound, 1 to2.5% by weight of a fatty alcohol ether sulfate, 0.7 to 1.0% by weightof a narrow-range fatty alcohol polyglycol ether, and 1 to 2.5% byweight of an electrolyte, selected from the group consisting of sodiumchloride and magnesium chloride, based on the weight of saidcomposition.
 2. A composition according to claim 1 wherein saidnarrow-range fatty alcohol polyglycol ether corresponds to formula (II)

    R.sup.2 O--(CH.sub.2 CH.sub.2 O).sub.m H                   (II)

in which R² is a linear or branched alkyl or alkenyl radical containing6 to 22 carbon atoms, and m is a number of 1 to
 10. 3. A compositionaccording to claim 1 wherein said peroxide compound comprises hydrogenperoxide.
 4. A composition according to claim 1 wherein said fattyalcohol ether sulfate corresponds to formula (I)

    R.sup.1 O--(CH.sub.2 CH.sub.2 O).sub.m SO.sub.3 X          (I)

in which R¹ is a linear or branched alkyl or alkenyl radical containing6 to 22 carbon atoms, m is a number of 1 to 10, and X is an alkali metalor alkaline earth metal, ammonium, alklammonium, alkanolammonium orglucammonium.